Abstract:

Abstract: Objective To explore the effect of cerebroprotein hydrolysate injection ( CHI) on learning and memory impairment caused by sevoflurane anesthesia in rats, and analyze its possible mechanism of action. Method Thirty-two rats were randomly divided into sevoflurane group, CHI high-dose group, CHI low-dose group and control group. The sevoflurane group inhaled 2% sevoflurane for 2 hours a day for 7 days. Before the daily inhalation of sevoflurane, 1 200 μL of CHI was injected into the tail vein of the CHI high-dose group and 300 μL of CHI was injected into the tail vein of the CHI low-dose group. The control group did not inhale sevoflurane, and injected normal saline into the tail vein. The water maze experiment was used to record the learning and memory abilities of rats; HE staining was used to observe the histopathological changes of rat hippocampus; ELISA was used to detect MDA and SOD levels in rat hippocampus; TUNEL was used to detect the apoptosis of rat hippocampal neurons; RT-qPCR was used to detect the expression of SYT1 mRNA in hippocampus. Western blot was used to detect the expression of SYT1, Bax, Bcl-2 and cleaved-Caspase3 protein in the hippocampus of each group. Result Compared with the control group, the escape latency was significantly increased in the sevoflurane group ( P< 0. 05) , the number of crossing platforms was significantly reduced ( P < 0. 05) , the residence time of the platform was significantly shortened ( P< 0. 05) , the neuron cells in the hippocampus were scattered, the borders were unclear, the nuclei were constricted, vacuoles appeared, the color was dark, the apoptosis rate of neurons in hippocampus was significantly increased ( P<0. 05) , MDA, Bax and cleaved-Caspase3 proteins were significantly increased, and SOD, Bcl-2, SYT1 mRNA and proteins were significantly reduced ( P<0. 05) . Compared with the sevoflurane group, the escape latency of the CHI high-dose group was significantly shortened ( P < 0. 05 ) , the number of crossing platforms was significantly increased ( P < 0. 05 ) , the residence time of the platform was significantly prolonged ( P < 0. 05 ) , the neuron cells in the hippocampus were arranged relatively tightly, the nucleus shrinkage and vacuoles were improved, the apoptosis rate of hippocampal neurons was significantly decreased ( P<0. 05) , MDA, Bax, cleaved-Caspase3 protein content decreased significantly, SOD, Bcl-2, SYT1 mRNA and proteins were significantly increased ( P < 0. 05) ; Compared with the model group, the CHI low-dose group had no significant changes in the various indicators of rats ( P > 0. 05) . Conclusion Pre-administration of high-dose CHI before inhalation of sevoflurane can improve learning and memory impairment in rats caused by sevoflurane anesthesia, which may be related to the reduction of oxidative stress injury, inhibition of hippocampal neuronal cell apoptosis and increase of SYT1 expression.

摘要：

摘要:目的 探讨脑蛋白水解液( CHI) 对七氟醚麻醉导致的大鼠学习记忆障碍的影响,并分析其可能作用机制。方法 将 32 只大鼠随机分为七氟醚组、CHI 高剂量组、CHI 低剂量组和对照组,每组 8 只。 七氟醚组吸入 2% 七氟醚,每天 2 h,连续 7 d,CHI 高剂量组每天吸入七氟醚之前,尾静脉注射脑蛋白水解液 1 200 μL,CHI 低剂量组每天吸入七氟醚之前,尾静脉注射脑蛋白水解液 300 μL。 对照组不吸入七氟醚,尾静脉注射生理盐水。 通过水迷宫实验记录大鼠学习记忆能力;HE 染色法观察各组大鼠海马组织病理学改变;ELISA 检测各组大鼠海马组织中 MDA、SOD 水平;TUNEL 检测各组大鼠海马神经元细胞凋亡情况;RT-qPCR 检测各组海马组织中 SYT1 mRNA 表达情况;Western blot 检测各组大鼠海马组织中 SYT1、Bax、Bcl-2、cleaved-Caspase3 蛋白表达情况。 结果 与对照组相比,七氟醚组大鼠逃避潜伏期显著增加( P<0. 05) ,穿越平台次数显著减少( P<0. 05) ,平台停留时间显著缩短( P< 0. 05) ,海马组织神经元细胞排列散乱,边界不清,细胞核固缩,出现空泡,着色较深,海马组织神经元细胞凋亡率显著升高( P<0. 05) ,MDA、Bax、cleaved-Caspase3 蛋白含量显著升高( P<0. 05) ,SOD、Bcl-2、SYT1mRNA 和蛋白含量显著下降(P<0. 05) ;与七氟醚组比,CHI 高剂量组大鼠逃避潜伏期显著缩短( P< 0. 05) ,穿越平台次数显著增加( P< 0. 05) ,平台停留时间显著延长( P<0. 05) ,海马组织神经元细胞排列相对紧密,胞核固缩和空泡现象得到改善,海马组织神经元细胞凋亡率显著下降( P<0. 05) ,MDA、Bax、cleaved-Caspase3 蛋白含量显著下降( P< 0. 05) ,SOD、Bcl-2、SYT1 mRNA 和蛋白含量显著 升 高 ( P < 0. 05) ;而 CHI 低 剂 量 组 大 鼠 各 项 指 标 与 模 型 组 比 并 无 显 著 改 善 ( P > 0. 05) 。结论 七氟醚吸入前预先给予高剂量 CHI 能够改善七氟醚麻醉导致的大鼠学习记忆障碍,其机制可能与降低氧化应激损伤,抑制海马神经元细胞凋亡和增加 SYT1 表达有关。